Yep, I'd like to see a comparison with the RX3 based on their similar price points, but would like to see comparisons of sound signatures, staging, pairing with high-end cans (HE-6, LCD2, HD800) and noise floor/low volume performance with sensitive IEMs. Balanced output of the RX3 can't be compared, of course.

Respectfully disagree. The obvious comparison for the Mk3-B is with the SR71B, not the single-ended amps. If you go back and read Skylab's last ever portable amp comparison, after reviewing roughly a hundred portable amps, he put the Triad Lisa III, Stepdance MKI and SR71B in the ring with his LCD-2 and the 71B, after lagging in single-ended mode, pulled ahead as soon as he went to balanced mode. Of course, that's one person's opinion, but I suspect that it sold a truckload of Ray's amps.

Like all the other balanced portable amps I’ve reviewed, the Mk3-B does suffer from the same shortcomings compared to the best of single ended portable amps. It doesn’t quite have the composure of high quality single ended amps, the mid range, the soundstage depth, image, and coherence, and so with highly resolving headphones like the HD800, I’d still take the Continental or the L3 over the Mk3-B. I think the sound is a bit grainy and not as clean as the Continental and the Triad Audio L3. I did enjoy the sound of the Mk3-B and HD800 pairing, but I just felt that it’s not the best combination that I’ve heard the HD800 out of.

Again, one person's view, and anyone crazy enough to want to drive the HE-6 from a portable amp has just one choice at this point in time, and its found in Portland, Oregon.

Compared to the other balanced portable amps in the market, the Mk3-B indeed is the best implementation I’ve found as it really has the guts to drive difficult headphones up to the Hifiman HE-6, while the SR-71B and the PB-2 amps fall short.

Make of that lot what you will - Mike and I havent always seen eye-to-eye, but I dont know anyone who can get gear as quickly as he can. Not sure if Mike can get the Portaphile, but he might be able to give us comparisons with the Continental and the L3.

improved clarity, details, bass control vs out of box. Im just starting to hear stuff ...breathing, tongue rolling and piano bench creaking (thought it was a fart at first) and background randomness. It's letting the CK10 do it's thing. Battery just went dead with a click/popEdited by NocKM - 6/9/12 at 11:53pm

Going from memory and at my age it is not a good thing the Portaphile 627 is more balanced in its presentation. The V2 Maxxed was great in the bass and low mids but the top end was not as open/extended as I liked, the new version is more extended, open, and the soundstage is more open as well. Of course all this from what I recall of the V2 Maxxed I owned a few years ago. Perhaps you could contact Cesar about a loaner/test unit.